I totally agree. The biggest thing I noticed my first few months of switching from windows to Ubuntu was that all my applications were managed through a secure pipe called the repository. The repository was filled using applications from a trusted source list which can be signed using a key. All my apps get security and functionality updates and I don't have to check every application provider to stay up to date. Nor do I have to hassle with more than the latest version crowding my hard disk.
If I had to make a top 5 list of linux features over other operating systems, #1 would be the package manager.
I think this is one area that Linux, particularly Debian Linux, has really innovated. Sure, there were software installation standards before, but one tool to find, install, fetch dependencies, and upgrade everything at once was pioneered by Debian.
But the innovators don't always end up being the successes. The iPhone and Android both have Debian-like package managers, with improvements to the discovery process. It wouldn't be unlikely that Apple would implement an App Store for OS X too, and Microsoft to follow suit.
If I had to make a top 5 list of linux features over other operating systems, #1 would be the package manager.